Releasing washover overshot



Nov. 4, 1952 R G, ALFQRD 2,616,749

RELEASING WASHOVER OVERSHOT 3 Sheets-Sheet 1 Filed Jan. 6, 1947 l7 l6 l5 R.G. ALF0RD INVENTOR. y EA (61 .83%

A T TORNFYS Nov. 4, 1952 R. G. ALFORD 2,5169749 RELEASING WASHOVER OVERSHOT Filed Jan. 6, 1947 3 Sheets-Sheet 2 INE ATTORNEYS Nov. 4, 1952 R. G. ALFORD 2,616,749

RELEASING WASHOVER OVERSHOT Filed Jan. 6, 1947 s Sheets-Sheet s R.G.ALFoRn IN VEN TOR.

ATTORNEYS Patented Nov. 4, 1952 2,616,7 49 RELEASIN'G' WASHOVER OVERSHOT Raymond G. Alford,'Houston, Texi assignor-to Houston Oil Field Material Company, a corporation Application January '6, 1947; -Seria1 No-. 7 2D,324

9 Claims.

The invention relates toa releasable overshot gripping device for fishing pipe from wells.

An object of the invention is to provide an overshot.for retrieving stuckpipe from a wellbore.

Anothernobject of theiinvention is to provide a gripping device-capable of being released from themember gripped.

:Another object of the invention is. to provide a gripping tdevic'e capable J of being released from the member-gripped whereinthe releasing mechanism is of simple construction and positive in action.

-Al'further :object :of the invention is to provide an -ove'rsho't for L gripping a 'ifish having an improved hmechanism for releasing the overshot from the lien grippedwliich eliminates the use of :tbreadsin the releasing mechanism, thereby reducing the possibility ofthe overshot becoming fouled during its operation.

.A still 'iurthereobj'ect of the-invention is to provide a .releasablezovershot: assembly having a minimum of Operativeparts.

Other objects and advantages-will become apparent withaconsideration of thefollowing description" and dra'wings wherein:

-F-ig. 1 is a 'verticalsectional viewof the device Showing an arrangement of .the parts thereof;

Fig. 2 is a -verticalxquarter sectional view of the clevice in engagement with :a pipe which is shown in elevation;

Figl 3 is a partial quarter, partial vertical sectional viewer the device showing the friction anchors in contact" with the pipe being gripped and 'l-the preferred means -l0f retaining the slip holder and slips in'idisengagement from the pipe ipp Fig.'- 4 is aisectional view on the line 4-4 of Fig. 3 showing a Jslot or keyway on the outer periphery -01 the upper friction carriage assembly and the corresponding .key on the body of the overshot;

:Fig. 5 is asectionalview on the line 5-5 of Fig. :10wis a vertical sectionalview of the body of the .device'showing the upper .portion of the slip holder and the swivel connection to the sleeve or: friction anchor carriage in elevation.

iIn Figrilthe tool is shown as being suspended from a collar? threaded internally at '3 to be connected toa stringofpipe (not shown) by which the 'devic'eis loweredinto the well bore. Such pipe may be of suitable diameter to telescope over the stuckpipe or fish, so'that liquid circulated downthrough the pipe will wash over the stuck pipe tending: and assisting in effecting its release.

'i'lheibody 4 oi the too1," enclosi-ng' the inner assembly; extends downwardly and is connected at itslower enditoaslip cage 5 which is in turn externally threaded at 6 for connection thereto of an eXtensionif-Adesired. L'I'his thread 6 may receive a rotary shoe-to help cut away material abcutithe stuck pipe.

I he 'slip g uides formedadjacent the upper inner end'oi the slip ca'getiare provided withinwardly tapered bearing surfaces 6, the inner end o'f-thesesurfaeesaending in the annular shoulder 9=which affords a stopmeans for the slips II]. The vertical radial shoulders ll form a dove tail to retainthezslips l fl incorrect longitudinal alignment-asthey slide downwardly onto the surfaces 8- cf-theslip guide I I. T-he slips ill have anc'uter.slide surface 12 complementary toib'eari-ng'suriaces 8. Teeth l3 on the inner surfaces of the slim ID afford better gripping action-cf the slips with the fish. The stems I i 4 extendupwardly fromeach of the slips and each is formed at-its top with the. lateral extensions t5 adapted to fit into the similarly cut slot It of the slip holder-l1.

The-slipsare retainedinposition in the slip holder b'y theinner surface of the body 4 on one side, -Fig.-1, and the sli'p' ret'ainer ring 18, Fig. 9, onthe otherside. An'yinumber of slips andslip guides may 'be provided.

'The annular groove is #0111 the outer. portion of the upper end of *the slip hanger or holder I1, and correspondinggrooveilfl on the inner periphery 'of the lowerend of the :sleeve .or wiper cage 2!, are arranged to receive swivel balls 22. Adja'cent the upper -end-cf the-sleeve, or wipercage 2i ,spaced windows23 are provided therethrough to receive the frictionanchors or wipers 24 secured thereat by suitable means such as the screws 25 and the cover plate 26.

The friction anchors 24 are arranged to extend inwardlyfrom the wiper cage 21 so as toengage the member gripped, as 'will be more fully described The body 4 is provided with the keys 21 on its inner surface to fit into the corresponding keyways 28 which are on the outer surface of wiper cage 2 l. The keyways 28 are shown as extending longitudinally of the wiper cage with the lower ends 29 thereof extending laterally from the keyways 28, as best seen in Fig. 3. The construction affords longitudinal movement of the wiper cage 2! and slip hanger H with respect to the body 4, while at the same time, slip holder [1 and slip cage ii are rotatable with respect to each other. While only a single key 2'! is illustrated in Fig. l, for ease of illustration, in practice, ordinarily two or more keys 21 are utilized, as best seen in Fig. 8. Y

In operation of the tool, it is run into a well bore on the lower end of a string of wash pipe. The sleeve, or anchor cage 2i, the slip hanger H, and slips in are free to move relative to the longitudinal axis of the body 4 of the tool as the tool passes over the fish to be gripped. The slips IE! are pushed upwardly by the fish or any couplings or tool joints thereon to allow the tool to pass downwardly thereover. As soon as the overshot has passed the tool joint 39, Fig. 3, the'slips immediately drop back into the slip guides l, to engage the pipe 3! below the tool joint 30 in order to frictionally engage and grip the pipe upon upward movement of the tool.

When the overshot has telescoped over the desired length of the fish, an upward pull may then be exerted on the connecting pipe (not shown) to produce relative movement between the body 4 and the slips ll thereby moving the slips inwardly to frictionally grip the fish. Inasmuch as the slips engage the fish while the tool is lowered and telescoped over the fish, upward movement of the body 4 causes the slip guides 8 to move upwardly relative to the slips 10 thereby moving the slips inwardly to frictionally grip the fish. Thus, an upward pull on the connecting pipe (not shown) causes an inward movement of the slips to frictionally grip the fish and thereby fix the fish relative to the body 4 and thus permit the fish to be pulled to the surface. If the fish 3i cannot be removed, or if for some reason the operator desires to disengage the tool from the pipe 3!, the tool is again lowered over the pipe until the friction anchors 24 engage a projection of the pipe 3| such as the tool joint 39 as best seen in Fig. 3.

When the friction anchors come in contact with the projection 38, this positions the sleeve, or anchor cage 2 l and the slip hanger ll with respect to the body 4 of the tool. The body 4 will continue to move downwardly moving the slip guides E8 downwardly relative to the slips Ill and thereby permitting outward movement and release of the slips from the fish. The downward movement of the body 4 also moves keys 2'] along the keyways 23. Rotation of the string of pipe connected to the tool moves keys 21 into lateral projecting keyways 29 locking wiper cage 2| and slip hanger H in elevated position away from slip cage 5. The tool may then be pulled upwardly from the fish 3|.

Broadly the invention contemplates a releasable wash over gripping device for pipes which contains a minimum of moving parts in its releasing and engaging mechanism.

What is claimed is:

l. A washover overshot adapted to be lowered into a well and manipulated therein to engage a fish comprising a body, a slip cage on'the lower end thereof having guide surfaces thereon, a slip 4 hanger thereabove, releasable supporting slips with slide surfaces thereon to cooperate with the guide surfaces of said cage, a wiper cage above said slip holder having spaced friction anchors thereon, said friction anchors being spaced from said fish but engageable by projections thereon, and said wiper cage and slip hanger being rotatablyconnected and slideably mounted in said body. 7

2. A device for gripping pipe comprising, a body, a slip cage thereon with inwardly tapered guide surfaces therein, a slip holder slidable in said body, a sleeve rotatably connected to said slip holder and slidable in said body, releaseable supporting slips with slide surfaces thereon to cooperate with said guide surfaces of said slip cage whereby downward movement of said slip holder and said said sleeve relative to said body moves the slips onto the guide surfaces of said slip cage and inwardly into contact with the member to be gripped, and friction means on said slip holder spaced from said pipe but engageable by projections thereon.

3. A device for gripping pipe comprising, a body, a slip cage thereon with inwardly tapered guide surfaces therein, a slip holder slideable in said body, a sleeve rotatably connected to said slip holder and slideable in said body, releasable supporting slips with slide surfaces thereon connected to said slip holder to cooperate with said guide surfaces of said slip cage so that upward movement of said body relative to said slip holder and sleeve moves the slips onto the guide surfaces of said slip cage and inwardly into contact with the member to be gripped, friction means on said sleeve spaced from said pipe but engageable by projections thereon whereby said friction means moves into contact with said projections on the pipe upon lowering of the body so that said sleeve and said slip holder are frictionally held against movement as the body is lowered so as to disengage the slips from the member gripped.

4. A device for gripping pipe comprising, a body, a slip cage thereon with inwardly tapered guide surfaces therein, a slip holder slideable in said body, a sleeve rotatably connected to said slip holder and slideable in said body, releasable supporting slips with slide surfaces thereon to cooperate with said guide surfaces of said slip cage so that downward movement of said slip holder and sleeve relative to said body moves the slips onto the guide surfaces of said slip cage and inwardly into contact with the member to be gripped, friction means on said sleeve spaced from said pipe but engageable by projections thereon, said friction means moving into contact with projections on the pipe upon lowering of the body so that said sleeve and slip holder are frictionally held against movement as the body is lowered so as to disengage the slips from the member gripped, and means operable upon rotation of said body to retain said sleeve and said slip holder in spaced elevation from said slip cage to maintain disengagement of the slips from the member gripped.

5. In a washover overshot for gripping pipe, a body, a slip cage and slip means having cooperating bearing and slide surfaces respectively, a slip holder slideable relative to said body to ef fect passage of the slips downwardly over the member to be gripped, friction anchors on the upper portion of said slip holder to contact projecting portions of the member gripped so as to hold the slip holder against movement during lower- 5 ing of said body to effect disengagement of the slips with the member grip, a key onf'said body, a cooperating keyway on said slip holder so that relative rotation of said body and saidslip holder retains said slip holder in inoperative position.

6. In a washover overshot to be lowered into a well and manipulated therein to grip a member, a pair of parts relatively movable to manipulate the washover overshot, upper and lower friction anchors on one part, said lower friction anchors adapted to engage a surface on the other part so as to retain said lower friction anchors in sliding engagement with the member to be gripped as the washover overshot is lowered, said lower friction anchors gripping said member when an upward pull is exerted on the second mentioned part, said upper friction anchors being spaced from such member but engageable by projections thereon whereby said upper friction anchors engage such projections on lowering the washover overshot thereby disengaging such lower friction anchors from the gripped member.

7. In a washover overshot to be lowered into a well and manipulated therein to grip a fish, a pair of parts relatively movable to manipulate the washover overshot, upper and lower friction anchors on one part, said lower friction anchors adapted to engage a surface on the other part so as to retain said lower friction anchors in sliding engagement with said fish to be gripped as the washover overshot is lowered, said lower friction anchors gripping the fish when an upward pull is exerted on the second mentioned part, said upper friction anchors being spaced from such fish but engageable by projections thereon whereby said upper friction anchors move into frictional contact with such projections on said fish when the washover overshot is lowered relative thereto to hold the first mentioned part against movement and to disengage the lower friction anchors from the fish gripped.

8. In a washover overshot to be lowered into a well and manipulated therein .to grip and-recover fish, first and second parts relatively movable to manipulate the washover overshot, upper and lower friction anchors on said first part, said lower friction anchors adapted to engage a surface on the second part so as to retain said lower friction anchor in sliding engagement with said fish as the washover overshot is lowered, said lower friction anchors gripping the fish when an upward pull is exerted on the second part, said upper friction anchors moving into frictional contact with the fish to be gripped when the device is lowered relative thereto to hold said first part against movement, and to disengage the lower friction anchors from the fish gripped, said first and second parts having respectively a keyway and a cooperating key to engage upon relative rotation of said first and second part to retain the lower friction anchors in disengagement from the fish gripped.

9. In a washover overshot to be lowered in a well and manipulated therein, a pair of parts relatively movable to manipulate the tool, upper and lower friction anchors on one part adapted to move inwardly into engagement with a member to be gripped, said upper friction anchors being limited in such inward movement with respect to the lower friction anchor whereby such upper friction anchors l are spaced from said member to be gripped but engageable by projections thereon on lowering the device thereby disengaging said lower friction anchors from said gripped member.

RAYMOND G. ALFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,812,059 Pryor June 30, 1931 1,816,207 Borgo July 28, 1931 2,070,869 Sorensen Feb. 16, 1937 2,394,832 Young Feb. 12, 1946 2,398,515 Brown Apr. 16, 1946 

